Process for removing deleterious acid components from steamed coffee

ABSTRACT

Roasted and ground coffee is subjected to a dearomatization, steaming operation prior to percolation of the coffee. The flow of extract in the percolators is then controlled such that it passes through the steamed coffee and then through a bed of unsteamed coffee. The unsteamed coffee deacidifies the extract which contains acids picked up from the steamed coffee.

United States Patent Pitchon 1 Feb. 22, 1972 [54] PROCESS FOR REMOVINGOTHER PUBLICATIONS DELETERIOUS ACID COMPONENTS S tz,C P Th l ,Vl.2,l96,.8- FROM STE AMED COFFEE 9ilve ofiee rocessing ec no ogy o 3 pp 5 [72]Inventor: Esra Pitchon, Flushing, N.Y.

. Primary Examiner-Frank W. Lutter [73] Assignee. general FoodsCorporation, White Plains, Assistant Examiner wimam L. MentlikAttorneyGerald E. Jacobs, Bruno P. Struzzi and Thomas V. [22] Filed:Nov. 19, 1969 Sullivan [21] A pl. No.: 878 227 p 57 ABSTRACT [52] US. Cl..99/7l Roasted and ground coffee is subjected to a dearomatization, f Mf U0 steaming operation prior to percolation of the coffee. The Fleld 0f..99/65, 71 flow of extract in the percolators is then controlled uchthat it passes through the steamed coffee and then through a bed of [56]Rem-em cued unsteamed coffee. The unsteamed coffee deacidifies the ex-UNITED STATES PATENTS tract which contains acids picked up from thesteamed coffee. 3,420,674 1/ 1969 McCartney ..99/71 7 Claims, NoDrawings PROCESS FOR REMOVING DELETERIOUS ACID COMPONENTS FROM STEAMEDCOFFEE CROSS REFERENCE TO RELATED APPLICATIONS New and Improved SolubleCoffee Process by Mansky et al., filed Nov. 10, 1969, Ser. No. 875,497.

BACKGROUND OF THE INVENTION This invention is for a method of treatingroasted and ground coffee in an extraction process whereby deleteriousacids formed by steaming coffee are removed. More particularly, itpertains to the use of fresh roasted and ground, unsteamed coffee as amedium for reducing the undesirable acids in coffee extract obtainedwhen extracting steamed coffee.

Many soluble coffee processes have been developed wherein volatilearomatic constituents are removed and recovered at different points inthe coffee process. These volatiles are collected and added back toeither the coffee extract prior to drying, or to the dry soluble solidsin order to enhance the flavor of the soluble coffee product. Many ofthese processes use the roasted and ground coffee which is to beextracted in a standard percolator operation as the source of thearomatic volatiles. The ground coffee is subjected to a steamingoperation and the vapors drawn off contain the desired volatilematerial. This steaming may be done under atmospheric conditions, undervacuum, or under elevated pressures depending upon which process isbeing used.

One of the undesirable side effects of steaming is the development ofacids which find their way into the coffee extract when the steamed,roasted and ground coffee is subjected to percolation. Severaltechniques have been suggested in the past for neutralizing or removingthese undesirable acids. Thus, one of the older techniques is toneutralize the acids chemically. This approach is apparently undesirableas the salty byproducts produced have an undesirable effect on theflavor of the coffee. In US. Pat. No. 3,420,674 a technique for treatingcoffee which has been subjected to atmospheric steaming is disclosed andclaimed. The process therein described involves subjecting the steamedcoffee to a vacuum operation in order to vaporize the acids and removethem in a vapor form.

While such a process apparently works it is also apparently restrictedto use of coffees which are atmospherically steamed and may not beeffective if the coffee is initially subjected to vacuum steaming.

SUMMARY OF THE INVENTION it has now been discovered that fresh roastedand ground coffee can be utilized as a medium for removing theundesirable acids from coffee extract obtained by subjecting steamedcoffee to a percolation operation. In a standard percolation operationthis invention is utilized by subjecting only part of the fresh coffeeloaded into a percolator column to a steaming operation. The remainderof the coffee in the percolator is unsteamed ground coffee. When thispercolator containing steamed and unsteamed coffees is put on steam, theflow of extract through the column is controlled such that the extractfirst passes through the steamed coffee fraction and then through theunsteamed coffee fraction.

It has been found that by practicing the process of this invention theacidity of the extract is significantly reduced, to a level approachingthat normally obtained when extracting unsteamed coffee in a percolatoroperation. The change in acidity is readily detected in the finalproduct and the lower acid coffee obtained by the process of thisinvention is much preferred.

DESCRIPTION OF THE PREFERRED EMBODIMENT Soluble coffee is normallyproduced commercially by subjecting roasted and ground coffee to waterextraction in a set of pcrcolators to obtain coffee extract containingsoluble coffee solids. Extract may then be further treated or directlysubjected to a drying operation.

The standard percolation operation is performed in a battery of columnscalled percolators. The operation is countercurrent in that water ispumped into the column containing the most spent or extracted groundsand is drawn off as an extract from the column containing the leastextracted or fresh ground coffee.

When using a steaming operation to obtain desired aromatic volatiles,the fresh coffee is steamed before it is subjected to extraction in apercolator. One such steam distillation treatment is described in US.Pat. No. 3,l32,947, wherein the roasted and ground coffee is subjectedto steaming at atmospheric pressure. There are many other patents whichdescribe steaming techniques which are performed under vacuum conditionsor under pressure.

In practicing the process of this invention the coffee may be steamed byany of the prior art processes. Also, the coffee may be steamed in thepercolator column or in a separate vessel prior to loading it into thepercolator column. The key to the success of this operation is to placea charge of steamed,

roasted and ground coffee in such a position that when the percolatorcolumn containing the steamed coffee is subjected to extraction, theflow of the extract will pass through the steamed coffee and thenthrough unsteamed coffee.

Thus, a percolator column can be partially filled with coffee which hasbeen subjected to a steaming operation followed by a charge of unsteamedcoffee to completely fill the percolator column. When this loaded columnis then put on stream in the extraction operation, extract will be fedinto the column at the bottom of the column, so that it will passthrough and extract the steamed coffee before it reaches and extractssolids from the unsteamed coffee. It has been found, that by followingthe process of this invention, the pH of the extract may be increasedfrom about 4.7 to almost 4.9. The pH of extract obtained from apercolator set wherein none of the coffee has been steamed was about4.9, when processing a particular blend of coffees. When this same blendof coffees has been subjected to a steaming operation the pH is found tobe about 4.7 due to the increase of undesirable acids formed during thesteaming operation. Thus, it is readily apparent that by practicing theprocess of this invention the acidity of the coffee is returned to anormal level with no added equipment being necessary to accomplish thisdesirable goal. The flavor of the extract and of the dry solids obtainedfrom the extract is significantly changed with a change in pH of aslittle as 0.05 to 0.10, with the lower acid (higher pH) extract beingsignificantly preferred. When practicing the process of this inventionthe extract obtained is equally preferred to extract produced whenunsteamed coffee is percolated, while the extract obtained from steamedcoffee is significantly different than and less preferred than extractobtained from unsteamed coffee.

The process of this invention may also be practiced by partially loadinga percolator column with unsteamed coffee and then filling the columnwith coffee which has been steamed. When loading the column in theforegoing manner, the flow of extract through the column will be fromthe top of the column down through the column and out of the bottom suchthat it will first pass through the steamed coffee and then through theunsteamed coffee.

An alternate to steaming coffee prior to loading the percolator columnwould be to partially load a percolator column with fresh coffee,subject the partially loaded column to a steaming operation and thencomplete the column loading with unsteamed coffee. The flow of extractin this instance would be from the bottom of the column up through thecolumn and out of the top so that the extract first contacted thesteamed coffee and then the unsteamed coffee.

It has also been found that a percolator column may be completely loadedand then subjected to a steaming operation by introducing the steam atsome point in the column between the top and the bottom and drawing offthe steam and ammatic volatiles either at the top or at the bottom ofthe column. in this manner only that portion of the bed between thesteam inlet and the point of drawoff is subjected to a steamingoperation and the remaining portion of the bed is used to deacidify theextract. Obviously, if the upper portion of the bed is subjected tosteaming, the flow of extract will be from the top of the percolatordown through the column and out the bottom. If the bottom portion of thebed has been steamed the flow of extract will be from the bottom of thecolumn up through the column and out the top.

In a copending application by Mansky et al., a unique percolationprocess is described wherein two fresh columns are put on stream. Adouble drawoff is taken from one of these two columns. The process ofthis invention is applicable to such a percolation technique bysubjecting one of the two columns to a steaming operation using theunsteamed column as the column from which the double drawoff is taken.In this manner, the extract first passes through the column containingthe steamed coffee and then through the column containing the unsteamedcoffee.

The process of this invention was demonstrated by the following example:

A battery of six percolator columns was used in a standard percolationoperation to produce coffee extract. The extract obtained duringequilibrium conditions was found to have a pH of about 4.9.

The process was then continued but with the added step of subjecting thecoffee in the fresh column to a steaming operation wherein all of thecoffee in the column was steamed before extract was allowed to flowthrough the column. It was found that the extract obtained had a pH ofabout 4.7 and was significantly less preferred than the extract obtainedfrom unsteamed coffee.

The run was then continued with the following modification:

Steam was introduced into the loaded fresh stage at a point one-thirddown from the top of the column; and a slight vacuum was applied at thetop of the column to direct the vapors up through the top one-third ofthe coffee in the column. After steaming, the extract flow through thiscolumn was in a downward direction from the top to the bottom of thecolumn. it was found that the extract obtained using this technique (theprocess of this invention) had a pH of greater than 4.8 and usuallygreater than 4.85. The extract thus obtained was significantly preferredover the extract obtained when using a column containing only steamedcoffee and was considered by expert tasters as essentially equivalent toextract obtained from the unsteamed coffee. The quantity of aromaticsobtained via partial column steaming was sufficient to impart anenhanced flavor when added back to the extract.

Having thus described the process of this invention it is intended to belimited and defined by the appended claims.

What is claimed is:

l. A process for removing the deleterious acid components of coffeeextract obtained from roasted coffee which has been subjected tosteaming for removal of volatile aromas and for producing an extractwhich is essentially equivalent to extract obtained solely fromunsteamed beans comprising: passing an extracting medium through a bedof said steamed coffee to obtain a coffee extract containing solublesolids extracted from said steamed coffee, said extract containingdeleterious acids formed during the steaming; passing said coffeeextract through a bed of roasted coffee which has not been steamed, saidextract being enriched by soluble solids extracted from the unsteamedroasted coffee and said unsteamed coffee filtering out deleterious acidspicked up from the steamed coffee.

2. The process of claim 1 wherein the steamed roasted coffee istransferred to a percolation column such that the bottom portion of thepercolator column is filled with steamed coffee; the upper portion ofthe percolator column is then filled with unsteamed roasted coffee andthe extracting medium is fed through the percolator column from thebottom to the top of said column.

3. The process of claim 2 wherein the percolator column IS filled withunsteamed coffee; steam is introduced into the column of roasted coffeeat the bottom of the column; the steam containing volatiles being drawnoff at a point between the bottom and top of said percolator column;after steaming the extracting medium being fed through the percolatorcolumn from the bottom to the top of said column.

4. The process of claim 1 wherein the bottom portion of a percolatorcolumn is filled with unsteamed roasted coffee; the top portion of thepercolator column is filled with steamed roasted coffee and theextracting medium is fed through the percolator column from the top tothe bottom of said column.

5. The process of claim 1 wherein a percolator column is filled withunsteamed roasted coffee; steam is introduced into the column of roastedcoffee at a point between the top and bottom of the percolator column;the steam containing coffee volatiles being drawn off at the top of saidpercolator column; after steaming the extracting medium being fedthrough the percolator column from the top to the bottom of said column.

6. The process of claim 1 wherein a percolator column is filled withunsteamed roasted coffee; steam is introduced into the column of roastedcoffee at a point between the top and bottom of the percolator column;the steam containing coffee volatiles being drawn off at the bottom ofsaid percolator column; after steaming the extracting medium being fedthrough the percolator column from the bottom to the top of said column.

7. The process of claim 1 wherein the percolator column is filled withunsteamed roasted coffee; steam is introduced into the column of roastedcoffee at the top of the column; the steam containing coffee volatilesbeing drawn off at a point between the top and bottom of the saidpercolator column; after steaming the extracting medium being fedthrough the percolator column from the top to the bottom of said column.

2. The process of claim 1 wherein the steamed roasted coffee istransferred to a percolation column such that the bottom portion of thepercolator column is filled with steamed coffee; the upper portion ofthe percolator column is then filled with unsteamed roasted coffee andthe extracting medium is fed through the percolator column from thebottom to the top of said column.
 3. The process of claim 2 wherein thepercolator column is filled with unsteamed coffee; steam is introducedinto the column of roasted coffee at the bottom of the column; the steamcontaining volatiles being drawn off at a point between the bottom andtop of said percolator column; after steaming the extracting mediumbeing fed through the percolator column from the bottom to the top ofsaid column.
 4. The process of claim 1 wherein the bottom portion of apercolator column is filled with unsteamed roasted coffee; the topportion of the percolator column is filled with steamed roasted coffeeand the extracting medium is fed through the percolator column from thetop to the bottom of said column.
 5. The process of claim 1 wherein apercolator column is filled with unsteamed roasted coffee; steam isintroduced into the column of roasted coffee at a point between the topand bottom of the percolator column; the steam containing coffeevolatiles being drawn off at the top of said percolator column; aftersteaming the extracting medium being fed through the percolator columnfrom the top to the bottom of said column.
 6. The process of claim 1wherein a percolator column is filled with unsteamed roasted coffee;steam is introduced into the column of roasted coffee at a point betweenthe top and bottom of the percolator column; the steam containing coffeevolatiles being drawn off at the bottom of said percolator column; aftersteaming the extracting medium being fed through the percolator columnfrom the bottom to the top of said column.
 7. The process of claim 1wherein the percolator column is filled with unsteamed roasted coffee;steam is introduced into the column of roasted coffee at the top of thecolumn; the steam containing coffee volatiles being drawn off at a pointbetween the top and bottom of the said percolator column; after steamingthe extracting medium being fed through the percolator column from thetop to the bottom of said column.